Miniaturization in the electronic industry placed a large number of discrete signal-receiving devices; e.g., integrated circuit chips, in tiny areas. The diameter of the signal-carrying wires was small enough taken alone, but the number required to connect a printed circuit board having a number of these devices thereon, created a bulky package. Cable consisting of a number of wires joined together by a common outer insulating jacket, called "ribbon cable", provided an initial answer but problems of cross-talk quickly caused workers in the field to seek an improved cable. An early effort resulted in a ribbon cable having a shield wrapped around it, such as disclosed in U.S. Pat. No. 3,634,782. Subsequently U.S. Pat. No. 3,663,739 issued, which taught wrapping a shield around each wire; i.e., around the dielectric surrounding each center conductor. Cross-talk between individual conductors as well as interference to and from the ribbon cable was effectively prevented.
The solving of one problem in this manner however brought about another problem; i.e., the termination of the shield from the cable to the connector. The shields in most common usage consist of a film, such as Mylar, coated with a conductive material. These kinds of shields prohibit all but very careful stripping of the outer insulating jacket. The methods and devices employed to connect the shields to contacts within the connector housing dictated a time-consuming piece-by-piece, hand operation.
Another type of ribbon coaxial cable utilizes a drain wire spirally wrapped about the dielectric surrounding the center conductor. The presence of a drain wire eased considerably the problems of providing a termination. However, the precise location of each spirally-wrapped drain wire on the periphery of the dielectric could not be ascertained prior to stripping the insulation. Further, the location of one drain wire did not necessarily have any relation to the location of the adjacent drain wire. Thus, while the termination was simplified, the unpredictable location of the drain wire stymied mass stripping and gang termination efforts.
These problems led one worker in the field to invent a ribbon coaxial cable of the type having a plurality of parallel center conductors each being surrounded by a dielectric and a foil shield and a drain wire running parallel to the center conductor and in direct contact with the shield. Each drain wire is located in the same angular position on each shield. Rapid and simultaneous stripping and termination was now possible. The aforesaid invention is disclosed in U.S. Pat. No. 3,775,552.
Subsequent to the invention of the ribbon coaxial cable having coplanar drain wires, a connector was invented wherein the housing contained two rows of contact-receiving cavities, one overlapping the other. The lower row of cavities provided contact orientation in a downward direction and the upper row of cavities provided contact oreintation in an upward direction. In use, all center conductors are terminated in contacts in one row and all drain wires terminated in the contacts in the other row. The width of this connector need be basically the same width as the width of the cable even through twice the number of wires were being terminated. This connector is disclosed in U.S. Pat. Nos. 3,864,011 and 3,907,396 and in application Ser. No. 528,294 filed on Nov. 29, 1974 now abandoned; 564,501 filed on Apr. 2, 1975 now abandoned 616,353 filed on Sept. 24, 1975. In conjunction with the aforementioned connector, a crimping tool was invented which has the capability of simultaneously or gang crimping all of the center conductors or all the drain wires in one operation. The connector is loaded into the tool and one set of wires; i.e., all the center conductors or all the drain wires, are fanned into position over the dual wire-in-slot termination ends of the contacts located in one row of cavities. The anvil of the tool presses the set of wires into the slots. The connector is then turned over and the second set of wires are likewise terminated in the contacts in the second row. The rate of termination using this crimping rool, which is disclosed in application Ser. No. 615,273, filed on Sept. 22, 1975, exceeds the rate of termination by other means at least five fold.
Subsequent to the development of the aforementioned inventions, it was found that some applications required a narrow connector but one in which all the contacts were orientated in the same direction.
Accordingly, the object of the present invention is to provide a connector for ribbon coaxial cable in which all the center conductors and all the drain wires of the cable are terminated in contacts orientated in the same direction.
Another object of the present invention is to provide a connector having a width only slightly greater than the width of the ribbon coaxial cable.
Yet another object of the present invention is to provide a connector susceptible to simultaneous or gang termination of all center conductors and all drain wires in a single operation.
These and other objects and advantages of the present invention will become readily apparent upon reading the following description in conjunction with the accompanying drawings.